class Solution {
public:
    bool isSumEqual(string firstWord, string secondWord, string targetWord) {
        int first=0,second=0,target=0;
        for(auto ch :firstWord)
        {
            first=first*10+(ch-'a');
        }
        for(auto ch :secondWord)
        {
            second=second*10+(ch-'a');
        }
        for(auto ch :targetWord)
        {
            target=target*10+(ch-'a');
        }
        return first+second==target;
    }
};